Wednesday, 20 January 2021

What are Reciprocating Compressors?

A reciprocating compressor is also known as a piston compressor. It acts on the principle of a positive-displacement compressor which is based on pistons that are driven through a crankshaft to provide high-pressure gases. The gases enter into the suction duct and follow the path of the compression cylinder to get compressed with the application of a piston that is rotating through a reciprocating motion. This motion is due to a crankshaft. Gases are then discharged through the output channel. Reciprocating compressors are used in oil refineries, gas pipelines, chemical plants, natural gas processing plants, air conditioning, and refrigeration plants.

Formation and structure

Talking about the formation and structure of the reciprocating compressor, it might come with different designs that vary from one to six or more, enough to quickly and efficiently compress gas during the compression process. With the compression process, the piston is driven with a reciprocal arrangement to compress the gas. These arrangements might be single-or dual-acting design. With the dual-action design, compression will take place on both sides of the piston. Whereas, in single-actin design, it takes place on one side of the piston.

With dual-action designs, when high-pressure applications are needed, the arrangement might turn into two piston rods on both sides of the piston to provide equal balance loads and enough power to compress gas from both sides. With such arrangements, loads are managed on both sides and cylinders are operated with the common crankshaft.

Defining the types of reciprocating compressors, they come in two types. One is High speed or separable compressors, and the other Low speed or integral compressors.

The separable reciprocating compressor is separate from its driver which might be an engine or an electric motor. A gearbox is required to rotate the compression train. It can cover the operating speed of 900 rpm to 1,800 rpm.

Separable reciprocating compressors come with several benefits like they are easy to install, require low cost, could be easily moved to different sites, and could also be bought with various sizes appropriate for your required space.

Integral reciprocating compressor

The other type is the integral reciprocating compressor which involves the power cylinders driving the compressor; installed integrally within the frame. These compressors might cover a speed of 200 rpm to 600 rpm. Their common use involves gas plants and pipeline services where fuel efficiency and long life is what you are carving for.

Talking about the components that make reciprocating compressors involve frame, cylinder, a distance piece, crankshaft, and piston, bearings, and compressor valves. The frame is made with rugged heavy metal and cylinders; being the compression chamber, is a metal container. This cylinder might be a double-acting or single-acting type. You can opt for cylinder material according to the pressure you need for compression purposes.

Distance piece

The next part distance piece separates the compression cylinder and compressor frame. Then comes the crankshaft which rotates the connecting rod, piston rod, and piston to get the compression process going. Piston, compression valves, and bearings are directly linked with compression and are responsible for pressure generation, load handling, and compression process. This way, the compression process takes place in reciprocating compressors.